add rector

composer.json

@@ -37,14 +37,16 @@
   },
   "require-dev": {
     "contao/test-case": "^4.0 || ^5.0",
-    "contao/manager-plugin": "^2.0",
-    "friendsofphp/php-cs-fixer": "^2.2",
+    "contao/manager-plugin": "^2.13",
     "phpunit/phpunit": "^8.0 || ^9.0",
     "php-coveralls/php-coveralls": "^2.0",
     "symfony/phpunit-bridge": "^3.2 || ^4.0 || ^5.0 || ^6.0",
     "heimrichhannot/contao-test-utilities-bundle": "^0.1.4",
-    "phpstan/phpstan": "^1.8",
-    "phpstan/phpstan-symfony": "^1.2"
+    "phpstan/phpstan": "^1.12",
+    "phpstan/phpstan-symfony": "^1.4",
+    "rector/rector": "^1.2",
+    "contao/contao-rector": "dev-main",
+    "symplify/easy-coding-standard": "^12.5"
   },
   "autoload": {
     "psr-4": {

rector.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+use Contao\Rector\Set\ContaoLevelSetList;
+use Contao\Rector\Set\ContaoSetList;
+use Rector\Config\RectorConfig;
+use Rector\Php84\Rector\Param\ExplicitNullableParamTypeRector;
+use Rector\Set\ValueObject\LevelSetList;
+use Rector\Symfony\Set\SymfonySetList;
+use Rector\TypeDeclaration\Rector\ClassMethod\AddVoidReturnTypeWhereNoReturnRector;
+
+return RectorConfig::configure()
+    ->withPaths([
+        __DIR__ . '/src',
+    ])
+    ->withRules([
+        AddVoidReturnTypeWhereNoReturnRector::class,
+        # In Vorbereitung für PHP 8.4:
+        // ExplicitNullableParamTypeRector::class
+    ])
+
+    ->withImportNames(importShortClasses: false, removeUnusedImports: true)
+    ->withSets([
+        LevelSetList::UP_TO_PHP_74,
+        SymfonySetList::SYMFONY_44,
+        SymfonySetList::SYMFONY_CONSTRUCTOR_INJECTION,
+        # Erst mit Symfony 6 (Contao 5) nutzen:
+        // SymfonySetList::ANNOTATIONS_TO_ATTRIBUTES,
+        ContaoLevelSetList::UP_TO_CONTAO_49,
+        ContaoSetList::FQCN,
+        ContaoSetList::ANNOTATIONS_TO_ATTRIBUTES,
+    ]);